Black vs Ruff

Black is a free, MIT-licensed formatter for Python code that follows PEP 8. It reformats whole files in place and uses a default line length of 88 characters. Its limited style choices are intended to keep code consistent across projects; indentation style cannot be configured. After formatting, Black checks whether the abstract syntax tree remains effectively equivalent and raises an error if the check fails. Install it with pip; it requires Python 3.10 or newer. The documentation lists editor integrations including Emacs, PyCharm, IntelliJ IDEA, Vim, Neovim, Visual Studio Code and Sublime Text, as well as GitHub Actions and doctest workflows. Notebook formatting is available with the jupyter extra, though Black skips cells containing certain magics or invalid syntax. It also includes blackd, an HTTP server that binds to localhost by default. Black is primarily a command-line tool and does not provide a Python interface. Stable releases preserve formatting within the same calendar year when the options match.

Ruff is a Python linter and code formatter written in Rust, available free under a permissive open-source license. It includes more than 900 built-in lint rules, including native versions of popular Flake8 plugin rules, and can automatically correct violations such as unused imports. Its formatter aims to serve as a replacement for Black, though the documentation allows for differences in some cases. The built-in Ruff Language Server supplies diagnostics, fixes, and formatting; the documentation recommends pairing it with another Python language server for navigation and autocompletion. Setup guidance covers VS Code, Sublime Text, PyCharm, and Zed, while CI support includes GitHub Actions, GitLab CI/CD, and pre-commit hooks. Ruff can be installed through uv, pip, pipx, standalone installers, Homebrew, Conda, and other package managers. It supports configuration in pyproject.toml, ruff.toml, or .ruff.toml. A Bandit-derived rule group checks for common Python security issues. Ruff runs on Linux, macOS, and Windows, and is also published as a Docker image. The maker describes it as 10–100x faster than tools such as Flake8 and Black.